title: Formation of 4(5)-methylimidazole and its precursors, α-dicarbonyl compounds, in Maillard model systems.
abstract: Glyoxal, methylglyoxal, and diacetyl formed from sucrose alone and from a D-glucose/ammonia Maillard model system were analyzed by gas chromatography. They are known as precursors of 4(5)-methylimidazole (MI). Glyoxal and methylglyoxal formed more in acidic conditions than in basic conditions, whereas diacetyl formed the most at the highest basic condition of pH 12. Glyoxal formation from sucrose ranged from 0.33 to 32.90 μg/g under four different time and temperature conditions. Amounts of glyoxal, methylglyoxal, and diacetyl formed in Maillard model systems ranged from 2.98 to 46.12 μg/mL, from 8.27 to 156.61 μg/mL, and from 14.94 to 1588.45 μg/mL, respectively. 4(5)-MI formation in the same model systems ranged from 28.56 to 1269.71 μg/mL. Addition of sodium sulfite reduced formation of these chemicals significantly. Total α-dicarbonyl compounds in 12 commercial soft drinks ranged from 5.75 to 50.72 μg/mL. 4(5)-MI was found in levels ranging from 1.76 to 28.11 ng/mL in 10 commercial soft drinks.
authors.affiliation: Department of Environmental Toxicology, University of California, Davis, California 95616, United States.
authors.forename: Hae Won
authors.initials: HW
authors.lastname: Jang
authors.forename: Yaping
authors.initials: Y
authors.lastname: Jiang
authors.forename: Matt
authors.initials: M
authors.lastname: Hengel
authors.forename: Takayuki
authors.initials: T
authors.lastname: Shibamoto
mesh_terms: D000641:Ammonia / Q000737:chemistry; D002253:Carbonated Beverages / Q000032:analysis; D002273:Carcinogens / Q000138:chemical synthesis; D002849:Chromatography, Gas; D003931:Diacetyl / Q000032:analysis / Q000138:chemical synthesis*; D005511:Food Handling / Q000379:methods; D005947:Glucose / Q000737:chemistry; D006037:Glyoxal / Q000032:analysis / Q000138:chemical synthesis*; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007093:Imidazoles / Q000138:chemical synthesis*; D015416:Maillard Reaction; D011765:Pyruvaldehyde / Q000032:analysis / Q000138:chemical synthesis*; D013395:Sucrose / Q000737:chemistry
chemical_list: D002273:Carcinogens; D007093:Imidazoles; D006037:Glyoxal; D013395:Sucrose; D011765:Pyruvaldehyde; D000641:Ammonia; D005947:Glucose; D003931:Diacetyl; C023439:4-methylimidazole